NIM05705 - Class 1 NICs: Expenses and Allowances: Mileage allowances: Types of mileage allowances
Mileage allowances may be based on a:
- fixed mileage rate paid for each mile travelled which includes all of the expenses associated with running a car
 - fixed mileage rate paid for each mile travelled to cover only the cost of fuel, plus a separate payment for associated running costs
 - round sum allowance which has no reference to the amount of miles travelled or any other considerations
 - monthly or annual lump sum based on an estimate of the costs likely to be incurred in using the car
 - combination of the above.
 
Most employers pay mileage allowances for business travel only but some may also pay allowances for private miles.